Forensic Examination

A forensic medical examination is a top-to-toe examination looking for injuries and taking samples that may be used as evidence in a police investigation and any subsequent prosecution. A forensic examination can be very time-consuming but is vitally important. Histories from caregivers should be obtained separately and as soon as possible; careful documentation is essential. A forensic examination should only be performed by a health professional who has the appropriate training and with appropriate facilities available. Much of the following can be applied to adults and younger patients.^{[1, 2]}

Forensic examination checklist

General principles

• Remember to take your time; look, record and look again; you only get one chance to get it right!
• Consult with the requesting officer and agree procedures.
• Obtain full informed consent (and record any failure of co-operation).
• Check antecedents; record a brief chronology of events.
• Think ahead; is the person fit to be detained/interviewed?
• Assess the patient's understanding and state of mind.
• Secure a chain of evidence; complete all required forms.
• Where required and appropriate, prescribe any treatment, and issue instructions for care.
• Consider whether a re-examination is necessary and when.
• Record abuse verbatim if possible.
• Record reasons for any refusal.

History

• Obtain the medical forensic history in a private, quiet setting.
• Consider and address the patient's needs prior to information gathering, including identifying the level of his/her communication skill.
• Ask about past medical history, current health, drugs or medicines.
• List the complaints.
• Ask for explanation of injuries seen and accurately record the answers.

Examination

• Carry out a general medical examination.
• Carry out a specific examination (eg vaginal and pelvic examination following sexual abuse/assault) and collect samples.
• Examine the body surface fully, or record why any areas were not examined.
• Use a magnifying glass on lesions; this can reveal information on causation.
• The record of the position of injuries should be unequivocal; use body diagrams/sketches.
• Consider whether photography is required (written consent is necessary); photographs of any injuries should ideally be taken by a qualified medical photographer.

Brief definitions

• Bruises (contusions): caused by blunt force, initially at point of contact, but can enlarge or track down tissue planes under the influence of gravity. May not be visible initially. Pattern may indicate the agent responsible, eg a number of 'finger' bruises on the upper arm, indicating the victim being grabbed.
• Petechial bruises sometimes reproduce texture of clothing, and may be produced by asphyxia.
• Abrasions: epidermal injury (not full thickness) always indicates the point of injury. One side may be raised, indicating the direction of the blow/injury.
• Lacerations: full-thickness skin injury, ragged, caused by blunt force. The shape may indicate the agent responsible.
• Incisions: sharp cutting implements, clean edges without abrasions.

Differential diagnosis

Consider differential diagnosis of injuries found on examination - for example:

• Bruises: accidental or nonaccidental injury, skin disorders, genetic disorders (eg Ehlers-Danlos syndrome), haematological disorders (eg leukaemia), Henoch-Schönlein purpura, Mongolian spots.
• Burns: accidental burn, dermatitis, skin infection, Stevens-Johnson syndrome.
• Fractures: accidental or intentional fracture, birth trauma, congenital syphilis, leukaemia, osteogenesis imperfecta, osteomyelitis, rickets, scurvy.
• Head trauma: accidental trauma, birth trauma, haemorrhagic disease, infection (meningitis or encephalitis), intracranial vascular anomalies, metabolic disease.

Investigations

Consider appropriate further investigations - for example:

• Dilated, indirect ophthalmoscopy (performed by an ophthalmologist): to detect retinal haemorrhages in children aged younger than two years.
• Head CT scan: to detect signs of injury or other pathology, eg brain abscess (MRI scan of the head if CT scan of the head is inconclusive).
• Laboratory investigations: for example, FBC (anaemia due to dietary deficiency, infection), LFTs, clotting factors, faecal occult blood test, urinalysis, and urine toxicology.
• Skeletal survey radiography: for suspected old and new fractures.
• Abdominal CT scan: if examination suggests abdominal trauma.
• Bone scan: to detect occult fractures.